ROLE OF THE HETEROTRIMERIC G-PROTEINS IN STROMAL-DERIVED FACTOR-1-ALPHA-INDUCED NATURAL-KILLER-CELL CHEMOTAXIS AND CALCIUM MOBILIZATION

The CXC chemokine stromal derived factor-1 alpha (SDF-1 alpha) induces both the chemotaxis and calcium mobilization in IL-2-activated NK (IA NK) cells. The ability of SDF-1 alpha to induce IANK cell chemotaxis i s inhibited upon incorporating antibodies to the alpha subunit of G(o) and G(q) but not G(i), G(s), or G(z), whereas (Ca++)(i) mobilization is inhibited with anti-G(i), anti-G(q), and anti-G(s), but not with an y other anti-G proteins examined. Further analysis showed that antibod y to phospholipase C (PLC)beta but not PLC gamma inhibited SDF-1 alpha -induced (Ca++)(i) mobilization, suggesting that this signal is mediat ed by G protein coupled receptor and not by tyrosine kinase receptors. Our results are the first to show that SDF-1 alpha is chemoattractant for NK cells, and that this effect is coupled to G proteins. (C) 1997 Academic Press.